1. Field of the Invention
The present invention relates generally to flapping apparatuses with large flapping angles and, more particularly, to a flapping apparatus which installed in a micro ornithopter and flaps the wings at relatively large angles. Therefore, even though the size of the wings of an ornithopter becomes smaller to reduce the size and weight of the entire body, the dynamic lift sufficient to fly the ornithopter can be generated.
2. Description of the Related Art
Generally, an ornithopter is an aircraft that flies by flapping its wings. Ornithopter research has been steadily conducted since Leonardo da Vinci's design of 1490, and the techniques pertaining thereto have made great and rapid advances. To date, a variety of ornithopters have been introduced. These ornithopters are being widely used, for example, not only as simple toys but also for industrial and military purposes, because remarkable effects can be obtained from the use of the ornithopters.
Meanwhile, conventional ornithopters use an engine, rubber band or compressed gas as a power source. An ornithopter with an engine has large output but is very noisy. In addition, it is not easy for a beginner to handle the engine and the fuel. In the case of a rubber band powered ornithopter or a compressed gas powered ornithopter, it is easy to handle the ornithopter but the flying time is relatively short and a user cannot easily control the direction or altitude thereof.
Recently, the development of a motor powered ornithopter is being promoted by rapid advances in motor and battery performance. The motor powered ornithopter does not require a separate engine or fuel, because it is operated by using a motor and a battery. Furthermore, if the battery is in the fully charged state, the ornithopter can fly for a long time. As well, reliable and smooth power transmission mechanism can realized.
The motor powered ornithopter constructed such that a power transmission unit is operated by a drive gear connected to a rotating shaft of the motor. Power required to flap the wings at an appropriate speed to produce the dynamic lift is transmitted to the wings by the power transmission unit. Furthermore, the wings are connected to the power transmission unit through a connecting rod that converts the rotation of the rower transmission unit into linear motion.
However in the conventional technique, the dynamic lift can be insufficient to lift a micro ornithopter, because the flapping angles of the wings are relatively small.